Mixing apparatus

ABSTRACT

An improved mixing apparatus is provided for intimately mixing together two or more materials such as resin, paints, and the like, in liquid form, without the introduction of air into the resulting mixture. The apparatus comprises a mixing unit having a circular cavity therein. Two separate impellors are driven in a counter rotational manner about the central axis of the cavity, each of the impellors having one or more radially extending blades. The blades have fingers positioned to intermesh with one another as the impellors are driven in the aforesaid counter rotational manner. The liquids to be mixed are introduced radially through an inlet on one side of the mixer unit and into the cavity, and the resulting mixture is discharged through a radial outlet which is positioned diametrically opposite the inlet, in accordance with an important feature of the invention.

ijnited States mm Re May 30, 1972 [54] MIXING APP TUS Primary ExaminerRobert W. Jenkins [72] Inventor: Carlo Re, Santa Ana, Calif. Attorneynlessup & Beecher [73] Assignee: Dyna-Shield, Inc., Santa Ana, Calif. [57] ABSTRACT [22] Filed: Nov. 9, 1970 An improved mixing apparatus is provided for intimately mixing together two or more materials such as resin, paints, and [21] Appl 87837 the like, in liquid form, without the introduction of air into the resulting mixture. The apparatus comprises a mixing unit hav- [52] US. Cl. ..259/6, 259/DIG. 3O i a ir l cavity therein. Two separate impellors are Int. Cl. driven in a ounter rotational manner about the central axis of [58] Field of Search ..259/95, 6, DIG. 30. 21, 41 the Cavity, cach f the impellors having one or more radially 259/105 103 extending blades. The blades have fingers positioned to intermesh with one another as the impellors are driven in the [56] References Cited aforesaid counter rotational manner. The liquids to be mixed UNITED STATES PATENTS are introduced radially through an inlet on one side of the mixer unit and into the cavity, and the resulting mixture IS 1,308,250 7/1919 Mortensen ..259/ 105 discharged through a radial outlet which is positioned diametl 1 943 Fadden 30 rically opposite the inlet, in accordance with an important fea- 2.203,980 6/1940 Burt..... ..259/D1G. 30 tum fth invention 2,952,448 9/1960 Cornell ..259/95 3 Clains, 4 Drawing Figures 7Z- Q (flea/ Va/Ve O E Cfiem I a/Ve I I I PATENTEDHAY 30 1972 SHEET 1 OF 2 ,m ur 6 Hare nw elvraz C ar/ 0 Arrak/u'r;

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MIXING APPARATUS BACKGROUND OF THE INVENTION Electrically energized mechanical mixers are in widespread use in many industries in which resins, paints, and other materials are to be mixed with one another, or with water, or other solvents. In cases where it is desirable to prevent air from being mixed into the mixture, the mixing process is carried out in a closed chamber. The present invention is con cerned with the latter type of apparatus Problems have been encountered in the prior art closed chamber mixing apparatus, in that difiiculties have been encountered in assuring that an intimate and homogeneous mix is achieved between the various ingredients; and to assure that there is no tendency for one of the ingredients, for example, to establish a path through the apparatus so as to be discharged without being intimately mixed with the others. Attempts to correct such a condition in the prior art have, for the most part, resulted in excessively complex, and expensive mechanisms.

The mixer of the present invention, on the other hand, is simple and inexpensive in its construction. Yet the mixer of the invention operates with a high degree of efficiency to assure that the various ingredients introduced into the mixing apparatus are thoroughly and intimately mixed with one another as they are discharged, the entire process being carried out in a closed system so as to preclude any possibility for the introduction of air into the resulting mixture. The mixer of the invention nullifies centrifugal forces which tend to cause the individual ingredients to be isolated at the edges of the prior art mixers.

The apparatus of the invention is predicated on the concept of providing a circular cavity in a mixer unit, and of driving two separate impellors in opposite directions about the central axis of the cavity. The impellors are equipped with toothed radial blades which extend to the edge of the cavity, and the teeth of the radial blades of one of the impellors mesh with the teeth on the blades of the other impellor as the impellors turn in opposite directions.

In the apparatus to be described, the ingredients to be mixed are introduced into the cavity of the mixer unit through a radial inlet at one side thereof, and the resulting mixture is discharged through a radial outlet of the mixer unit positioned diametrically opposite the inlet. The assembly is such that the ingredients introduced through the inlet must pass through the impellor blades and must be intimately mixed with one another. That is, there is no possible path through the cavity of the mixer unit along which the ingredients from the inlet can pass to the outlet without being intimately mixed with one another.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational representation, in somewhat schematic form, showing apparatus constructed in accordance with the invention;

FIG. 2 is a view of a mixer unit which constitutes a component of the apparatus of FIG. 1, the mixer unit being shown in perspective and with one cover removed to reveal its internal components;

FIG. 3 is a section through the mixer unit taken essentially along the line 3-3 of FIG. 1; and

FIG. 4 is another section through the mixer unit taken essentially along the line 4-4 of FIG. 1.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT The mixer apparatus shown in FIG. 1 includes a mixing unit 10. The mixing unit 10, as shown in FIG. 2, defines a central circular cavity 12 therein which constitutes the mixing chamber. The ingredients to be mixed in the mixing chamber 12 are introduced into the cavity through an inlet 14 which extends radially through the mixing unit and through the side wall of the cavity 12. The resulting mixture from the chamber 12 is discharged through a radial outlet 16 and through an outlet hose 18 (FIG. 1) the radial outlet 16 is positioned diametrically opposite the inlet 14.

A pair of drive motors 20 and 22 are mechanically coupled to impellors within the cavity in the mixing unit 10 by means of respective shafts 24 and 26. The shafts 24 and 26 extend along the central axis of the mixing chamber 12 and coaxial relationship with one another. The motors 20 and 22 drive the shafts 24 and 26 in a counter rotational manner, so that the impellors within the cavity are rotated in opposite directions about the central axis of the cavity. The same effect may be achieved by a single motor and a counter rotating gear or belt coupling system.

As best shown in FIG. 3, the mixing unit 10 is composed of a first section 10a and a second section 10b, the two sections being bolted to one another. The shafts 24 and 26 may be composed, for example, of stainless steel, or other suitable material. The shaft 24 is rotatably mounted in the hub of the section 10b in appropriate bearings 30 which may, for example, be Oilite bearings. The shaft 26, on the other hand, is rotatably mounted in the hub of the section 10a on similar bearings 32.

The shaft 24 drives an impellor 36 in one direction about the central axis of the cavity or chamber 12, and the shaft 26 drives an impellor 38 in the opposite direction. As shown in FIGS. 3 and 4, the impellors 36 and 38 have radial blades which extend to the edge of the cavity or mixing chamber 12, and the blades have teeth or fingers formed in them, as best shown in FIGS. 3 and 4. As the impellors rotate in opposite directions, the teeth or fingers of ther respective blades intermesh with one another, as best shown in FIG. 3.

It will be appreciated that when the ingredients to be mixed are introduced through the inlet 14 at one side of the mixing chamber or cavity 12, they must pass through the blades of the impellors 36 and 38, and the passage through the oppositely rotating'impellor blades causes the ingredients to be intimately mixed before being discharged through the outlet 16 at the opposite side of the chamber 12.

The liquid ingredients to be mixed in the mixing unit 10 are introduced to the inlet, for example, through an inlet line 40. In the illustrated embodiment, and as shown in FIG. 1, the inlet line 40 is connected to a pair of hoses 42 and 44 through a coupling 46 and through a pair of check valves 48 and 50. The hoses 42 and 44 extend from the outlet of corresponding pumps 52 and 54, and hoses 56 and 58 are coupled to the inlets of the respective pumps.

The hoses 56 and 58 extend to the receptacles, or other containers which hold the various ingredients which are to be mixed in the mixing apparatus. It will be appreciated, of course, that although two separate hoses 56 and 58, and associated elements, are shown for interrnixing two separate ingredients, three or more ingredients may be mixed, merely by coupling similar elements into the inlet line 40. The pumps 52 and 54 are driven, for example, by an electric motor 60 and through individual belt drives 62 and 64.

A hose 70, which extends to a source of purging liquid is also coupled to the inlet line 40 through the coupling 46, and through a manually operated valve 72. At the end of any mixing operation, the motor 60 is de-energized to cut off the supply of the ingredients, and the valve 72 is opened so as to permit the purging liquid to flow through the apparatus and clean the mixing unit and its operating components.

The apparatus described is simple and inexpensive in its construction, and yet it operates with a high degree of efficiency to perform its intended purpose. It will be appreciated that while a particular embodiment of the invention has been shown and described, modifications may be made, and it is intended in the claims to cover all modifications that come within the spirit and scope of the invention.

I claim:

1. Mixing apparatus including: a mixing unit defining an internal cavity having a circular configuration; a first impellor mounted for rotation in said cavity about an axis extending through the center of said cavity and having at least one blade member having integral teeth and extending radially with respect to said axis across the entire width of said cavity to the edge thereof; a second impellor mounted for rotation in said cavity about said axis and having at least one blade member having integral teeth positioned to intermesh with said teeth of said first impellor and extending radially with respect to said axis across the entire width of said cavity to the edge thereof; drive means coupled to said first and second impellors for imparting counter rotational motion thereto about said axis so as to cause the teeth of said first and second impellers to mesh with one another as said impellors are driven with the aforesaid counter rotational motion about said axis; said mixing unit having an inlet positioned at one side thereof and extending radially into said cavity, and said mixing unit further including an outlet positioned diametrically opposite the aforesaid inlet and extending radially from said cavity.

2. The mixing apparatus defined in claim 1 and which includes an inlet line coupled to said inlet, and means including separate pump means for introducing the material to be mixed into said inlet line.

3. The mixing apparatus defined in claim 2, and which includes means including a valve for selectively introducing a purging liquid into said inlet line. 

1. Mixing apparatus including: a mixing unit defining an internal cavity having a circular configuration; a first impellor mounted for rotation in said cavity about an axis extending through the center of said cavity and having at least one blade member having integral teeth and extending radially with respect to said axis across the entire width of said cavity to the edge thereof; a second impellor mounted for rotation in said cavity about said axis and having at least one blade member having integral teeth positioned to intermesh with said teeth of said first impellor and extending radially with respect to said axis across the entire width of said cavity to the edge thereof; drive means coupled to said first and second impellors for imparting counter rotational motion thereto about said axis so as to cause the teeth of said first and second impellors to mesh with one another as said impellors are driven with the aforesaid counter rotational motion about said axis; said mixing unit having an inlet positioned at one side thereof and extending radially into said cavity, and said mixing unit further including an outlet positioned diametrically opposite the aforesaid inlet and extending radially from said cavity.
 2. The mixing apparatus defined in claim 1 and which includes an inlet line coupled to said inlet, and means including separate pump means for introducing the material to be mixed into said inlet line.
 3. The mixing apparatus defined in claim 2, and which includes means including a valve for selectively introducing a purging liquid into said inlet line. 